Older pup becoming possessive/protective of youger puppy

[Multiple Doodles (or dogs)]

Sherlock is my 10 month old maltipoo (11lbs). He and Noah (my 5 month goldendoodle, 17lbs) are best friends and when we're at the dog park, they tend to play only with each other. I've noticed that Sherlock has become increasingly possessive and protective of Noah. If another dog tries to play with them (particularly a bully breed, boston, pug, frenchie - all dogs that Sherlock doesn't care for), Sherlock will snap at the dog to get him away. If the dog is a poodle, maltese, coton, pom (basically a cute fluffy dog), Sherlock doesn't care as much. If a dog starts picking on Noah and gets him on his back, Sherlock will rush over and jump in front of Noah and try to protect him. If a big dog comes over to them and sniffs Noah and Sherlock gets the wrong vibe, he'll literally try to fight off a big dog (he's tried this with pit bulls, shar-peis, newfies, etc....) I'm worried he'll try it to the wrong dog some day and be eaten as lunch! Additionally, if Sherlock goes to greet a person and the person is petting him, when Noah rushes over to be pet as well, Sherlock will start barking at the person if they start petting Noah. On occasion, if someone tries to pick Noah up, Sherlock will start barking. I'm trying to take them out separately so they get used to being alone. They are in different obedience classes and I try to take them to separate play groups or to the park individually. I take them out to train individually each night. At this point, I would say Noah is way more attached to Sherlock than Sherlock is to Noah, but Sherlock is protective of Noah. Noah is a bit shy when Sherlock is not around. Has this happened to anyone else? Does anyone have any suggestions? When Sherlock tries to snap* at a dog, I correct him and hold his collar so he can't chase the dog and to give him a time-out. Should I be doing this? I guess I should ask my trainers these questions, but just wanted to see if anyone else had a similar experience...
*Sherlock has snapped at dogs, but he never puts his teeth on them. He has never bit a dog or person, but I don't like the noises he makes when he snaps. Most dogs never even take this seriously because they always come back for more. He never bullies other dogs, but if he doesn't like a dog, he'll tell that dog to go away. He never humps other dogs. Dogs used to pick on him when he was really little and a puppy, but now they don't because he has matured quickly. He has never even been in a scuffle at the dog park. He is very playful and acts really differently at the park when Noah isn't there.

[Tante & Jordan & now Annie!]

Sherlock sounds just like my Jordan. I talked to an animal behaviorist she said Jordan was acting like a normal alpha female. She has her dogs she likes, and her dogs she does not.She makes it known. I do not take Jordan to dog parks or to where there are large groups of dogs off leash. I make sure I know who she playing with and the owners understand Jordan. I am taking small steps. Maybe some day I take her to a Doodle Romp which I would love to do.
When Jordan reacts to dogs, I usually let her work it out with the dog. It is what I was told to do. It still feels wrong to me,I feel as if I should go back to leashing her and time out. The AB I talked to said Jordan was saying Do not do that. Jordan is bossy and she HATES if I pet another dog.Unless she knows that dog.
One interesting thing is when Jordan got together with her litter mate Koda they both did it to each other, then they played very well each other.That is Jordan's thing once the dog backs down she is fine.I am in fear of the day she meets the dog that does not back down.I think that would lead to fight.It is why I stopped going to Dog parks.
I posted a Blog about my consult with the AB if you want to read it.It might help.

I would love anyone's ideas on here also.
Tante

[Tante & Jordan & now Annie!]

Sounds like my Jordi, I socialized her so much. She was like this at 10w in puppy class.It when our trainer 1st said You need to make sure you keep her socialized. I did back to back training until she was 2. Thank Goodness she has great recall. It has saved us many times. Jordan dislikes all the wolf breeds. Husky,German Sheps etc. She loves Pit Bulls. Dh thinks it is dogs that are bigger than her.She will react to small dogs also.So I am not so sure. I think it is what ever that dogs energy is. I cant tell if is the ones who are Higher or lower than her in the dog ranking world.
I really would love Cesar Milan's help,but with out the whole dominance thing. I think he has great advice but Jordan is not a red zone case and she is well trained. 3 trainers and 1 AB think I worry too much about it.
I found a place out here called Fido's Farms they do training and they are a dog Hotel. I might take her there for help.I cant imagine leaving her someplace. She is my Snuggle Doodle.
Oh and Jordan hates to be sniffed....by any dog.

[Allyson, Peri & Taquito]

Well, Taquito is getting increasingly more protective of his sister Peri. Which is not good because he is going to mess with the wrong dog and get attacked one day. We were walking during lunch today and he literally ran across Peri to get in between her and an incoming Greyhound. He used to like Greyhounds! IT is getting worse and worse - especially when they are on leashes. Not so much at a dog park or anywhere else.

Today I had to pick him up to keep him from charging two other dogs. Meanwhile Peri lays down in submission, wanting to play!
HELP!
Jane, did Sherlock get better????